The invention relates to non-focusing photographic lenses, specifically to conical lenses.
Prior spherical-lens art is concerned primarily with spherical lenses which project rays through a focal point onto a film placed a distance away from the lens.
Prior conical-lens art includes the Conical Beam Concentrator, U.S. Pat. No. 4,333,713, June 8, 1982, by this inventor. The upper component lens of this invention has a plano face which receives an incident beam which is perpendicular to the face and a convex conical face which refracts the incident beam, forming a convergent conical beam.